Here's a bit about the differences between 360 and PC mods (got this in about 3 mins worth of work):
For those of you that don't know, the official plug-in files (plug-in files are called ESP files, correct?) for the PC and 360 versions of Oblivion are exactly the same...
Below are a few MD5s for a few official plug-in files:
Vile Lair PC:
2C51FF6C5196A334377F41A5EC7159E5
Vile Lair 360:
2C51FF6C5196A334377F41A5EC7159E5
Horse Armor PC:
12733AD9718557860AE8C14BC7EB11CA
Horse Armor 360:
12733AD9718557860AE8C14BC7EB11CA
BSA files, as far as I know, are the same as well, except they have special archive and file flags (which, btw, are supported by BSA Commander).
Sound: .mp3 files have to be in a .xma format (xbox 360 audio format... can be built with XMA sound tools)
LIP files are again (as far as I can tell) identical:
sound\voice\dlcvilelair.esp\breton\m\dlcdeepscorn_goodbye_00004b9f_1.lip (PC) md5:
2AF3E7A60C13CC7FEB3435520A05EEFA
sound\voice\dlcvilelair.esp\breton\m\dlcdeepscorn_goodbye_00004b9f_1.lip (360) md5:
2AF3E7A60C13CC7FEB3435520A05EEFA
texture files: PC textures are in .dds format where the 360 textures are in .ddx format (I am assuming that the .ddx files are general xbox 360 testure files, not game specific, but i can't say for sure without doing a bit of research).
meshes: .nif files (both use v20.0.0.5, although are compatible with a few different versions as far as i know).
differences between pc and 360 nif files:
360 version has "BSPackedAdditionalGeometryData" whereas PC version has "NiBinaryExtraData" don't know what they are but i'll try looking into it.
conclusion: except for a few differences in data (textures, sounds and meshes), the mods are more or less exactly the same